Chair base



Nov. 19, 1 935.

A. R. LAFFERTY 2,021,187

CHAIR BASE Filed Jan. 2, 1934 2 Sheets-Sheet l INVENTOR {ii/7dr R Lafferlg $45k", 49a! ATTORNEYS Patented Nov. 1 9, 1935 Arthur R.

Laflerty, Detroit, Mich,

assignor to Burroughs Adding Machine Company, Detroit, Mich., a corporation of Michigan Application January 2,1934, Serla1 No.704,840

5 Claims. (01. 155-438) A more particular object is to provide a sheet metal chair base constructed mainly of one member formed to provide the legs and which when assembled may be retained in form by a minimum,

number of auxiliary parts.

In constructing a chair base of metal it is not only desirable to have the construction and assembly as simple as possible but at the same time to have the chair base present a pleasing appearance. The present invention has been directed to the provision of such a'construction.

Another object is therefore to provide an improved sheet metal chair base which is pleasing in appearance. 4

Other objects of the invention will appear from the following specification and drawings.

I An embodiment of the invention is shown in the accompanying drawings in which- Figure 1 is a perspective view of an oiiice chair illustrating the novel construction of the chair base.

Fig. 2 is a-perspective of the chair base from the underside.

Fig. 3 is a spread perspective of parts comprising the complete chair base with the partssepa rated to show the manner in which the parts are assembled.

Fig. 4 is a detail perspective of the caster retainer used in the chair base legs.

Fig. 5 is a sectional view through thecenter of the chair base showing the details ofconstruction and the method of fastening the different parts together.

The illustrated chair is of the executive type and embodies a seat ill from the sides of which arms ii and a back i2 extend. The seat is mounted upon a swivel post !3 carried by the base indicated generally by the reference character is. The complete chair may be conveniently disassembled and shipped to any point where it may be readily assembled by the purchaser.

The main member of the chair base which constitutes the subject matter of this invention is formed from a single sheet of flat steel cut the proper size and formed or stamped to provide four spaced supporting legs. The flat sheet of steel from which the chair base legs are formed is so cut and shaped that after the stamping and -6 forming operations have been completed, to provide four equally spaced legs substantially U- shaped in cross section, the only trimming necessary is at the outer ends of each leg, to provide a flat uniform surface for receiving the caster re- 10 tainer l5 (Fig. 4) These retainers are also formed from sheet metal and are provided with slightly resilient or yielding side walls l6 which will permit the retainers to be sprung into openings in the ends of each base leg, after which they may be spot welded thereto.

The lower edges of the side walls I! of the legs are flanged inwardly for a portion of their length to provide strengthening flanges I8 which add rigidity and strength to the leg member. The opposed side walls I! of adjacent legs are connected by integral curved side wall portions l9 and are further joined by an integral top wall 2 I.

A star-shaped lower plate 22 is provided-and is formed with four crescent shaped upwardly ex- 25 tending curved flanges 23 which flanges when the plate is in position fit snugly within, 1. e., underlap thecurved wall portions IQ of the legs as best shown in Fig. 5. The flanges 23 are welded to the curved wall portions l9 throughout substantially their entire contacting surfaces and the surplus welding material 24. which extends beyond the shoulder of the outer overlapping wall portion I9 is ground .off to form a rounded surface'as is clearly shown in Fig. 5 to provide a Smooth jointure between the curved wall I9 and the flanges 23. This prevents scuiiing of the users shoes and perhaps damaging their wearing apparel, and also presents a smooth, rounded, finished surface after the base is painted. 40

To support and position the lower plate 22 during assembly and while it is being welded to the main base element, plate 22 is provided at each point with a pair of laterally projecting lugs 26 which engage the edges of the leg .walls ll of the four legs and support the plate in position while it is being assembled and welded. The lugs are preferably of such thickness that during the welding process they are burned away or they may be ground oh so as to leave no projections.

A reinforcing plate 21 (Figs. 3 and 5), shown as a rectangular plate, may be placed immediately above the upper surface of the lower plate 22 to give further rigidity and strength to the assembly. This reinforcing plate or member dis- 'as at 20 When a swivel action is desired as in the case of the illustrated executive chair, a swivel race Ii rests upon the upper end of bushing 28 and is secured to the upper end of a sleeve 82 which is inserted within the bushing II, the sleeve being of suiiicient length to project below the lower end of the bushing where tongues 33 are struck outwardly therefrom and peened over the lower end of bushing 28 to prevent withdrawal of sleeve 3! and race II.

From the foregoing description it will be apparent that there has been provided a sheet metal chair base of simple construction and exceedingly few parts although the assembly and construction are such as to provide for absolute rigidity and durability over long and hard usage.

It will be apparent to those skilled in the art that minor changes may be made in the details of construction without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A sheet metal chair base comprising-a single piece of sheet metal formed to provide a plurality of spaced legs substantially U-shaped in cross section Joined by integral and connecting side walls and a top wall. a lower plate bridging the open central portion of said legs beneath said top wall having portions lapping and welded to the connecting side walls, the welding metal at the lower end of the side wall and plate providing a smooth Joint between said plate and side wall, a reinforcing plate of a thicker gauge than said base and lower plate overlying said lower plate, and a tubular member extending through said top wall, said reinforcing plate and said lower plate securing them together.

2. A sheet metal chair'base comprising a sin-,

gle piece of sheet metal formed to provide a plurality of spaced legssubstantially U-shaped in cross section Joined by integral and connecting side walls and a top wall, a lower plate'bridging arranged to engage said legs positimi said plate during assembly. said lugs bespams? theopen central portion of said legs beneath said top wall having portions lapping and welded to the eonnectingside walls, the welding metal atthelowerendofthesidewallandplateproa smooth joint between said plate and 5 side wall, a tubular member and secured to said top wall, extending through saidtubular member and lower plate. and a swivel race secured to the upper end of said sleeve and resting upon the upper end of said tubular member, said, inner sleeve extending below the lower end of said tubular memher and having outwardly struck tomes engaging said member. v

3. A-sheet metal chair base comprising a single piece or sheet metal formed to provide a pluralivoi pecedlessioinedbyln sml a necting side walls and a top wall, and a lower plate under the top wall and having portions lapping and secured to the connecting side so walls. said plate also having positioning lugs arranged to engage said legs to support and position said lower plate during assembly of the chair base. v -4.Asheetmetalchairbasecomprisingasin-z5 gle piece of sheet'metal formed to provide a plurality of spmd legs Joined by integral and connecting side walls and a top wall, anda lower plate underlying said top wall and having portions underlapping and welded to the connecting side walls. said plate also having positioning lugs to support and lng suiiiciently thin to burn away during weldl I e s5 5. A sheet metal chair base comprising a single piece of sheet metal formed to provide a plurality of spaced 1m substantially u-shaped in cross section 'Joined by integral and connecting side walls and a topwall. each leg having an opening 40 through its underside at its outer extremity adapted toreceive a caster retainer, a lower plate bridging the open central portion of said legs beneath said top wall and having portions lapping and: welded to the connecting side walls, the 4g welding metal at the lower end of the side wall and plateproviding a smooth Joint between said plate and side wall. and a sheet metal caster retainer having slightly resilient side walls into said openings on the outer extremities of said legs and retained by wel ARTHUR R. mm. 

